Torque tube.

[TroyBranch]

Ready to rivet the aft torque tube to the control. The manual says use green loctite and the kit is shipped with 401 loctite. Should I rivet and let it wick in? Or do I get green loctite. The 401 drys to fast to use like the manual shows. I assume the glue is because there is less rivets on the aft torque tube? What have you guys done?


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[EVRoosevelt]

I just bought a bottle of the green stuff
EV

[TroyBranch]

Per Mitch,

The green loctite is more of a bearing type. They want us to use it to take up any slack in the tube.

The 401 is for the fuel fittings.

[jmorrical]

One other issue bothers me about my torque tube installation so far. When I got the front torque tube bushings and stiffener torqued in place it felt to me that roll movement force required to rotate the tube would be way too stiff. How do you tell if it's too stiff?

Mitch suggested I might need to fabricate and install a very thin aluminum shim between the front top and bottom bushing. Any recommendation?

Jim Morrical

[ceslaw]

Jim

FWIW, it did feel a bit stiff when first installed. But try moving it from the end of the control stick - better judge of 'stiffness'. Also once the plane is rigged and with a bit of usage the 'stiffness' became a non issue. It is nice and smooth now.

I would rather have it a bit stiff than loose.

Also, worst case scenario, add the shim at the end when everything is done, if it is still an issue.

Chuck

[jmorrical]

Thanks Daveemby. That would be great.

Yes, ask him about the tube, masts and bushings diameter and fit. Have you seen the Service Bulletin - SB 00015 Rev C Effective date: Sept 13, 2011 requiring some serial numbers to check for torque tube to mast tightness?

I wonder what changes were made on later serial numbers to correct for this SB?

When I first played with the masts and tube on a level surface I notices the fit was very tight. Any side force on the mast while trying to slide it on or off just locked it up. And when you are working it thru the floor it is hard to line the parts up and keep them from binding. And you simply can't put the same amount of force on the parts when they are in place on the floor.

Also, I noticed on the bushings there were markings that I didn't pay much attention to the first time I put it together. Now I notice the "hieroglyphics" seem to have some order, so I wonder if the bushings are a matched set some how? Or can they simply be paired together in any order. Ask that too if you would please.

I wonder if that 90 IN-Lbs torque is still the correct torque for those bushings. I still think on my install there is way too much force required to rotate the mast in the lubricated bushings. This suggests something is not sized correctly. I haven't installed a shim Mitch suggested however. At 70 IN-Lbs torque the tube rotated with a reasonable force.


Jim Morrical

[Pete D]

Thanks Daveemby. That would be great.



I wonder what changes were made on later serial numbers to correct for this SB?


Jim Morrical

Later S/N a/c have a thicker wall torque tube and more rivets. The SB kit includes both of those upgrades.

[Daveembry]

Later S/N a/c have a thicker wall torque tube and more rivets. The SB kit includes both of those upgrades.

Thanks. So no change to the diameter of the TT? Mine is 1.498". I just torqued my front bearings to the 90 ft lbs and it seems to be just right......not too tight at all. I haven't done the rear yet as I'm waiting to see what to do with the stuck rear mast. But, it doesn't seem to be a problem with front bearing tightness.

[jmorrical]

My instructions in the fuselage manual for the EX on page 54 shows a picture of red Loctite and calls for RED Loctite. I guess I'll use Loctite 271 which was shown in the list of materials in the first few pages of the manual.

Jim Morrical

[TroyBranch]

271 is just a thread locker. You want retaining compound loctite.


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